fix(contract): support inconsistency testing EVM time

[airinterface]

Pull Request Template

Description

Please include a summary of the changes and the related issue. Please also include relevant motivation and context. List any dependencies that are required for this change.

Fixes # (issue)

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Screenshots

If applicable, add screenshots to help explain your problem.

[Copilot]

Pull Request Overview

This PR fixes timing inconsistencies in EVM contract tests by replacing strict equality assertions with more flexible range-based assertions. The change addresses the inherent timing uncertainty in blockchain testing environments where block timestamps may not be precisely controlled.

• Replaces exact timestamp matching with acceptable range assertions (±1 second tolerance)
• Adds comprehensive documentation explaining the EVM timing behavior
• Updates multiple test assertions to handle timing edge cases consistently

[Copilot]

The timing tolerance logic is duplicated across multiple test assertions. Consider extracting this into a helper function like expectTimeWithTolerance(actualTime, expectedTime, tolerance = 1n) to reduce code duplication and improve maintainability.

Suggested change

	expect(elapsedTime).to.oneOf([
	expectedElapsedTime,
	expectedElapsedTime + 1n,
	expectedElapsedTime - 1n,
	]);
	expectTimeWithTolerance(elapsedTime, expectedElapsedTime);

[Copilot]

[nitpick] The comment explains the timing behavior well, but it should be moved to the top of the test function or extracted as a module-level comment since this timing issue affects all assertions in the test, not just this specific one.